Simulation And Experiment Of Cerasus Humilis Air Screen Cleaning Device Based On EDEM-FLUENT Coupling

Cerasus humilis is a unique dwarf shrub fruit tree in China.It has high economic and nutritional value and has a broad development prospect.In recent years,in order to realize mechanized harvesting of Cerasus humilis,domestic related scholars have devoted themselves to research and design of mechanical harvesting device of Cerasus humilis,and achieved some achievements.However,the high impurity content of Cerasus humilis after mechanical harvesting is not conducive to further intensive processing of Cerasus humilis.In order to reduce the impurity content of Cerasus humilis after mechanical harvesting,this paper measured the physical properties related to the mechanical harvesting of Cerasus humilis and provided theoretical reference for the design of the cleaning device with the help of EDEM-FLUENT coupling simulation technology.The processing and manufacture of the cleaning device of Cerasus humilis were designed and verified by bench test.The results are as follows:(1)The national standard measurement method was adopted to measure the physical properties related to the mechanical exfoliation of Cerasus humilis,including the composition and composition ratio of the exfoliation,shape and size,mass,density,suspension velocity,friction coefficient and recovery coefficient between the exfoliation and different materials.The measured physical parameters provide data support for subsequent coupling simulation and device design.(2)According to the physical characteristics of Cerasus humilis and the requirements of "Agricultural Machinery Design Manual",a kind of air screen type Cerasus humilis cleaning test device was designed,and its composition and working principle were analyzed.And the main components of the further description and size design.and the preliminary selection of test factors.(3)Fluent and EDEM are coupled by Eulerian-Eulerian mathematical model,in which EDEM adopts Hertz-Mindlin no-slip contact model to simulate the collisions between particles,between particles and screen surface,and between particles and the inner wall of cleaning screen.Fluent uses RNG-K flow field model to simulate the variation law of gas velocity and pressure in cleaning device.(4)With wind speed of fan,vibration screen amplitude and frequency as test factors,and Cerasus humilis cleaning rate and loss rate as evaluation indexes,EDEM-Fluent coupling was used to design single factor simulation test,and the test results were analyzed.According to the simulation test results,the structural parameters of the test bed were optimized.The influencing factors are wind speed of fan,amplitude and frequency of vibrating screen.(5)With the wind speed of the fan,the amplitude and frequency of the vibrating screen as the test factors,and the cleaning rate and loss rate of Cerasus humilis as the evaluation indexes,the bench test was carried out to verify.The single factor test results show that when the wind speed of the fan and the vibration frequency and amplitude of the vibrating screen increase gradually,the cleaning of the screen type cleaning device increases firstly and then decreases,and the loss rate increases gradually.The results are in good agreement with the simulation results.The orthogonal test shows that: the wind speed of the fan is10m·s-1,the vibration amplitude of the vibrating screen is 10 mm,and the vibration frequency of the vibrating screen is 9Hz,which is the optimal cleaning parameter combination of the screen type cleaning device.Under the optimal combination of cleaning parameters,the cleaning rate of the device is 96.3% and the loss rate is 3.4%.